Apparatus for removing corners



June 5, 19,45. 5 Q JOHNSON 2,377,558 APARATUS FOR REMOVING CORNERS Original Filed Dec. 12, 1940 Patented June 5, 1945 APPARATUS FOR REMOVING CORNERS Bernard C. Johnson, Mundelein, Ill., assignor to Houdaille-Hershey Corporation, Detroit, Mich., a corporation of Michigan Original application December 12', 1940, Serial No. 369,722. Divided and this application May 1, 1944, Serial No. 533,545 r 2 Claims. (Cl. 78-60) This invention relates to apparatus for forming rounded edgeson metal articles to eliminate sharp edges in order that coating material will uniformly cover the articles.

. Specifically the invention deals with apparatus for pressing the aperture mouths of sheet metal evaporator units to eliminate all sharp, edges therefrom in order that the evaporator unit can bejuniformly coated with protective film such as zinc.

This application is a division of my copending application entitled: Method of making evaporators, U. S. Serial 369,722 filed December 12, 1940. a

While the invention will be hereinafter specifically described in connection with sheet metal evaporator units, it should be understood that the apparatus of this invention is useful in removing sharp edges from the aperture mouths of metal articles in general.

Metal articles having sharp edges cannot be uniformly coated, since the coating film will be quite thin at these edges and, in numerous instances, the sharp edges will project through the film. In the manufacture of sheet metal evaporator units from inexpensive metal suchasmild steel, it is necessary to thoroughly protect all exterior surfaces of the units with a protecting film. Such sheet metal evaporator units are usually galvanized or tinned, and it is very difficult to cover the sharp edges of the units with .such a protective film inasmuch as the film will draw thin or break entirely at the edges of the article. V

The present invention now provides apparatus for dressing the sharp edges and corners of a sheet metal evaporator unit to provide rounded contours thereon which are readily covered with a protective film. The dressing operations are performed by pressing the annular aperture mouths of the sheet metal unit. A die press is used to round off the sharp aperture mouths. These dressing operations are preferably effected prior to the bending of the unit into its final shape and while the same is still in a fiat condition.

It is, then, an object of the invention to prepare the aperture mouths of sheet metal articles for coating by dressing these mouths to form a rounded contour thereon.

A further object of the invention is to provide apparatus for working the metal around the'aperture mouths in sheet metal articles to eliminate sharp corners or angles therefrom.

A further object of the invention is to provide a rounded contour.

a die press for acting on. the apertures of sheet metal articles to round out the aperture mouths and eliminate sharp corners thereon.

A specific object of the invention is to provide a die press with an enveloping sleeve for pinchingmetal adjacent an aperture in a metal article to squeeze the metal around the aperture to Other and further objects of the invention .Will be apparent to those skilled in the art from the following detailed description of the annexed sheet of drawings which, by way of preferred examples, illustrate two embodiments of the invention. On the drawing:

aperture mouth.

Figure 4 is a plan view of an apertured metal sheet illustrating a rounded aperture mouth formed in accordance with this invention.

Figure 5 is a cross-sectional view taken along the line V--V of Figure 4 and illustrating the uniform protecting film covering the sheet metal.

Figure 6 is a view similar to Figure 5 but illustrating the defective protecting film formed when the aperture mouths are sharp.

As shown on the drawing:

In Figures 1 and 2 the reference numeral I0 designates generally a metal article composed of metal sheets II and I2 secured together along contiguous faces thereof by means of a bond such as aweld l3. The article ID has a circular aperture l4 through bothsheets II and II. The

aperture 14 has sharp mouths l5, IE on each sheet II and [2. The article I0 is mounted on die IS with the aperture l4 receiving the leading end of the die. die has a quarter-round bevel or groove ll. A top die I8 having a similar leading end witha grounded groove l9 cooperates with the die Hi. The dies 16 'and [8 are telescoped by sleeves 20 and 2| respectively which have rounded leading ends 22 The leading ends 22 of the sleeves press into the faces of the sheets I l and 12 to flow the metal into the aperture l4. As the dies close, the grooves 11 and. [9 form a semi-cylindrical pocket This leading end of the dies will dress the sharp corners i5, j l5 0f the aperture 14 sufficiently to f orm a rounded .contour, although this rounded i cont'our nay not be as smooth as that obtained with theuseof the sleeve.

As shown in Figures 4 and "5,- the finished unit H] with the rounded hole 14 canbegalvanized to 7 form the protective film 24 thereon. This protective film 24 will flow through the aperture l4 and be uniformly deposited thereon as at25. If,

on the'other "hand, as" shown in Figure 6, the corriers I5, 15 are allowed to remain'around the aperture mouth M, the -film"24 will not uniformly flow through the aperture and will draw thin or rupture as at 26.-

From the above descriptions it will be understood that the invention provides apparatus for the elimination of sharp corners'from'apertures through she'et 'metal articles in order that coating material will uniformly flow through the apertures to provide a protective film for the metal covering all exposed surfaces.

It wil1,-of course, be understood that various details of the invention may be varied through a wide range without departing from the principles of this invention and'it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

I' claim as'my invention:

1. Apparatus for removing sharp corners from --apertured metal articles which comprises a pair of cooperating dies havin leading ends with "quarter round peripheral grooves cooperating to qprovide asemi-cylindrical recess, and sleeves enveloping said dies having rounded leading ends for flowing metal into the recess.

2. Apparatus for removing sharp corners from spermred metal articles which comprises a pair of cooperating dies having leading ends with rounded peripheral'grooves therearound' adapted tdc'ooperate to provide a rounded recess,"and

sleeves enveloping said dieshaving leading-ends for acting on metal-articles inserted between the dies to flowmetal of the articlesintojthe' recess and provide apertures in the articles with smooth rounded defining walls.

' BERNARD C. JOHNSON. 

